Strong vibration above 50 mph

Post by **miel.gerritse** » Sat Jul 11, 2009 1:40 pm

In only a very short period of several weeks (with not much miles) my Morris (1963, 1098cc, RHD) developes very strong vibration at the front when the speed comes at 50 mph or above. No vibration at the steering wheel though.
I checked if anything was loose, it wasn't. No play at the wheel bearing or loose wheelbolts, or tie-rods

It seems that there is some play in the steering rack (plenty of oil in it), which I notice when moving the wheel while someone else holds the steering wheel tight. Could it be the damper in the steering rack? Anyone else have a suggestion?

Many thanks,

Miel Gerritse
The Netherlands

Post by **rob.hardy1** » Sat Jul 11, 2009 1:48 pm

have you had the wheel balacing checked? i had the same symptoms after removing the wheels for renovation

Post by **miel.gerritse** » Sat Jul 11, 2009 2:02 pm

I do not think it is the balance. I mean, at first there were no vibrations and nothing has been changed to the wheel(s).
To be sure I will check if the balancing weights are perhaps have come loose.

Miel

Post by **Declan_Burns** » Sat Jul 11, 2009 3:15 pm

I had a vibration problem above 50 mph and it turned out to be the prop shaft in the end. It took me ages to pinpoint it. Worth a check.

Post by **Dru** » Sat Jul 11, 2009 3:29 pm

I had the same prob, which took ages to pinpoint. Turned out to be the forward universal joint on the propshaft. At least checking the UJ's is a quick and easy job, and then you will have eliminated one possibility.

Post by **cormorant** » Sat Jul 11, 2009 5:22 pm

It sounds silly but my car did the same and the problem? Worn out rubber bushes in the rear springs giving metal to metal contact - set up a vibration in the whole car, didn't feel like it was coming from the rear. Only above 50mph too.
Poly bushes zijn veel beter

Sat Jul 11, 2009 5:46 pm

My first thought was going to be "wheel balance" but given that the steering wheel is not vibrating I would have to say that is more than likely your prop .. like others above mine has gone in the past.. it was fine when i drove into the petrol station but not when i came out of it! I was lucky my local moggy place pointed straight to it.

Post by **Declan_Burns** » Sat Jul 11, 2009 6:44 pm

Yes it's strange indeed. After replacing all the bushes front and back and changing the damper oil, I suspected the prop as a last resort, tried the jubilee clip trick-didn't help-I replace the UJs and it got worse! I probably re-assembled it 180° out even though I marked it with Tipp-ex before I took it apart , but having said that getting the old UJs out was a hell of a job as eyes broke off the old circlips the minute I touched them-that's when the fun started. In the Haynes manual it states that you can press them out with your fingers!! Ha! ha!- The bench vice wasn't enough, I had to beat hell out of them to shift them-I suppose that didn't help and the Tipp-ex marks were gone! I should have taken a photo.
Popped in a second hand prop-problem more or less eliminated! There is a spot at about 52mph where there can be a slight vibration which I just drive through-sometimes you don't notice it at all. I must get the old prop re-balanced if it's not too expensive so at least I have a spare.
All very strange!

Miel's problem could however lie elsewhere.

This is well worth a read:
http://www.christran.net/mmpropshaft.htm
I wonder what ever happened the guy-it's a pity he never continued his work as I thought his website was very good and informative.

Post by **bmcecosse** » Sat Jul 11, 2009 11:06 pm

Swap the front wheels/tyres with the rear ones - is the vibration just the same ?

Post by **David53** » Sun Jul 12, 2009 12:02 am

Rotating the wheels is a good idea - I had the same problem years ago when mine was originally on the road. Turned out to be a rear tyre slightly out of round, had a slight bulge on the tread. When I put it on the front it shook the wheel. I replaced with the spare and the vibration magically dissapeared

Post by **bmcecosse** » Sun Jul 12, 2009 12:21 am

Yes -that's what I was thinking!

Post by **rayofleamington** » Sun Jul 12, 2009 1:21 pm

the tyres can give problems - especially when old! If damp gets though the rubber (easy when the tyre is perished) the steel braiding can rust away. This allows the tyre to 'fall apart' and in the process it develops lumps / bulges and/or out of roundness.
If you jack the car up so the tyre is ~5mm off the ground and spin the wheel - the gap should stay equal. If the gap changes as you spin the wheel or if the tyre wobbles around, you've got a tyre problem.

Personally I'd guess this one is more likely to be the prop, but time will tell.

Post by **bmcecosse** » Sun Jul 12, 2009 3:54 pm

To check the prop for wear - get under the car (securely held on ramps etc!) and grab hold of the prop and waggle it about . If there is any 'play' - that could very well be the problem. But I think it's likely to be tyre related!

Post by **miel.gerritse** » Sun Jul 12, 2009 4:40 pm

Thank you all for your advice. I will check both the wheel by exchanging front and rear and will replace the UJ's in the prop. I have spare ones so this round will only cost me time. Next weekend I hope I can tell you if the problem is solved and what the cure was.

Thanks again.

Miel Gerritse

Post by **bmcecosse** » Sun Jul 12, 2009 8:45 pm

If there is no 'play' in the prop shaft -it's not needing new joints. Swap the wheels first.

Post by **miel.gerritse** » Wed Jul 29, 2009 10:51 am

Okay, so this is what I did next:
I changed the wheels, rearright to front left etc. Vibrations seemed to change as well when testdriving, but they did not disappear. So I had the wheels balanced. They appeared to be slighly out of balance (all four) so I hoped this would cure it.

Testdriving proved wrong, vibration still present. When on the bridge I could check the play in the UJ and there was a very, very slight play in the rear UJ.
As balancing the wheel did not solve anything, it could only be the UJ's, or not? More so, because I did the following test: driving at +50mph (with vibration), I put the gearbox in neutral and immediately the vibration increased considerably. I strongly suspect the drivetrain (backaxle or propshaft).
I will keep you updated after renewing the rear UJ.

Best regards, Miel

Post by **bmcecosse** » Wed Jul 29, 2009 4:33 pm

Check the prop isn't bent!

Post by **miel.gerritse** » Wed Jul 29, 2009 7:32 pm

I will, but if that's the case that surely could only be caused by a serious blow, couldn't it?

Post by **bmcecosse** » Wed Jul 29, 2009 9:07 pm

Or someone jacking up under the prop - or the car grounding on a hump in the road.

Post by **mike.perry** » Wed Jul 29, 2009 9:53 pm

Prop shafts can go out of balance for no obvious reason. I have had the problem on two Minors, vibration at 50 to 55 then smooth again.
I had the propshaft on the MM rebuilt and balanced and it solved the problem. With a M1000 it is probably just as easy to get a spare prop shaft.

Morris Minor Owners Club

Strong vibration above 50 mph

Strong vibration above 50 mph

Strong vibration over 50 mph

vibration above 50mph